Evaluation of the clinical, biochemical, genotype and prognosis of mut-type methylmalonic acidemia in 365 Chinese cases

BACKGROUND: -type MMA in Chinese patients. METHODS: -type MMA; investigated their disease onset, newborn screening (NBS) status, biochemical metabolite levels, gene variations and prognosis; and explored the relationship between phenotype and genotype. RESULTS: gene, including 52 novel variations. c.729_730insTT, c.1106G>A, c.323G>A, c.914T>C and c.1663G>A were the five most frequent variations. The c.1663G>A variation led to a milder phenotype and better prognosis. CONCLUSION: responsive and late onset are favourable factors for the prognosis.